If we want to have better control on the DatePicker behavior, we pass the
AsDatePicker method an instance of the DatePicker control.
For example, lets change the date format, and add a js callback for after a date was selected:

The AutoComplete Extender sends 2 arguments to the Controller: the user’s input (userInput), and the max amount of results it is configured to show (resultCount).
The Controller, need to pass back a Json representation of an AutoItemList.

Now that we have the Controller configured, lets create the actual AutoComplete TextBox:

Like the DatePicker, the AutoComplete is an Extender, which means it adds the AutoComplete behavior to an existing input (the txtValue TextBox in this example).
The only required arguments are: how to call the hidden input it will store the value of the selected item (valueId), and what is the Controller’s Action to invoke (searchUrl).

The Result:

Have a look at the AutoComplete class for additional supported customizations.